First Steps: Starting and Stopping ROOT
Starting and stopping ROOT. Installation problems. ROOT Commands.
Command line recall.
To start ROOT, all you need to type is:-
This should produce a banner rather reminiscent of the one produced by
PAW and then wait for commands. If this does not happen the you need to
check the ROOT installation.
Not to be too ambitious in the first session, type:-
which tells ROOT to quit. Don't omit the leading dot! ROOT should now
You can type two sorts of input into ROOT, or any application, such as
MINFAST, that is based on ROOT:-
- ROOT commands such as .q. These are always preceded with a dot.
We shall introduce a few of the more common ones as we go along, but if
you want to see the full list then take a look at:-
- C++ statements. CINT can cope with most C++ statements although it
cannot currently handle a few advanced ones such as certain complex
template statements. However, it can deal with everything the beginner
needs so is a good tool to learn the language. C++ is a very poor
interactive command language and so CINT permits some
that make life easier. Of course this is counter productive if you are
trying to learn the language so, for the most part, these extensions
should be avoided.
ROOT uses the VMS/tcsh style command line recall. You can press up arrow
repeatedly to scroll up to recall previous commands and then use the
left and right arrows to position within the command before editing and
The ROOT tutorial
Starting an Interactive Session
explains how it is possible to customise ROOT by editing a set of
initialisation and termination script files in much the same way as the
.cshrc file is used to customise a csh session.
should run ROOT. If it doesn't check $ROOTSYS is
defined and that $ROOTSYS/bin is in your path.
- ROOT commands start with a dot. The command .q quits ROOT.
The full list is
- ROOT include the CINT C/C++ Interpreter which means that C++
commands can be typed directly into ROOT which is a great way to learn
C++, but avoid those
- ROOT includes the VMS/tcsh command line recall system.
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